Based on the three different graphene nanoribbons discussed in last section,
there are four types of AB-stacked BLG ribbon, which can be summarized by
the tight-binding Hamiltonian [1]}, [2]}, [3]}
\(H=\sum _{l}H_{\mathrm {edge}}^{l}+H_{\mathrm {int}}+H_{\mathrm {on-site}},\) 
